Williams Learning Network. (1999). Electric motors: DC motors. Williams Learning Network.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रWilliams Learning Network. Electric Motors: DC Motors. Rockville, MD: Williams Learning Network, 1999.
एमएलए (8वां संस्करण) प्रशस्ति पत्रWilliams Learning Network. Electric Motors: DC Motors. Williams Learning Network, 1999.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.